1. Field of the Invention
The present invention relates generally to the field of semiconductor fabrication, more particularly to the field of safely disposing of effluent gases from semiconductor processing equipment, and most particularly to low-maintenance devices for coupling processing equipment exhaust lines with gas scrubbers, and methods for delivering effluent gas streams into gas scrubbers.
2. Description of the Prior Art
A number of manufacturing processes, including those directed to producing semiconductor devices, produce quantities of effluent gases that cannot be released into the atmosphere without appropriate cleaning. One technique that is effective for cleaning many types of effluent gas streams, such as those that result from etching metal layers, is to pass the effluent gases through a gas scrubber. The scrubber sprays a liquid, typically water or another solvent, through multiple nozzles at the top of a chamber. Effluent gases enter the chamber through one or more inlets in the top of the chamber near the nozzles so that the gases rapidly interact with the spray. Although the nozzles direct the spray downward into the chamber and away from the inlets, mist from the spray nevertheless tends to enter the inlets. Where the mist enters, compounds from the effluent gases can nucleate from condensation or precipitate from the reaction with water and over time, sometimes quite rapidly, grow to form a mass that clogs the inlet. This, in turn, leads to expensive down-time as the processing system has to be shut down to clean the scrubber inlet.
Therefore, what is needed are apparatus for coupling gas scrubbers to processing equipment exhaust lines that resist clogging, and methods for delivering effluent gas streams into gas scrubbers that inhibit the formation of clogs and provide for clearing any clogs that do form without incurring down-time for associated processing equipment.